 /*******************************************************************************
  * Copyright (c) 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.expressions;

 import java.util.ArrayList ;
 import java.util.Iterator ;
 import java.util.List ;

 import org.eclipse.core.expressions.EvaluationResult;
 import org.eclipse.core.expressions.Expression;
 import org.eclipse.core.expressions.ExpressionInfo;
 import org.eclipse.core.expressions.IEvaluationContext;
 import org.eclipse.core.runtime.CoreException;

 /**
  * Copied from org.eclipse.core.internal.expressions.
  */
 public abstract class CompositeExpression extends Expression {

     private static final Expression[] EMPTY_ARRAY = new Expression[0];

     protected List fExpressions;

     public void add(Expression expression) {
         if (fExpressions == null) {
             fExpressions = new ArrayList (2);
         }
         fExpressions.add(expression);
     }

     public Expression[] getChildren() {
         if (fExpressions == null) {
             return EMPTY_ARRAY;
         }
         return (Expression[]) fExpressions.toArray(new Expression[fExpressions
                 .size()]);
     }

     protected EvaluationResult evaluateAnd(IEvaluationContext scope)
             throws CoreException {
         if (fExpressions == null) {
             return EvaluationResult.TRUE;
         }
         EvaluationResult result = EvaluationResult.TRUE;
         for (Iterator iter = fExpressions.iterator(); iter.hasNext();) {
             Expression expression = (Expression) iter.next();
             result = result.and(expression.evaluate(scope));
             // keep iterating even if we have a not loaded found. It can be
 // that we find a false which will result in a better result.
 if (result == EvaluationResult.FALSE) {
                 return result;
             }
         }
         return result;
     }

     protected EvaluationResult evaluateOr(IEvaluationContext scope)
             throws CoreException {
         if (fExpressions == null) {
             return EvaluationResult.TRUE;
         }
         EvaluationResult result = EvaluationResult.FALSE;
         for (Iterator iter = fExpressions.iterator(); iter.hasNext();) {
             Expression expression = (Expression) iter.next();
             result = result.or(expression.evaluate(scope));
             if (result == EvaluationResult.TRUE) {
                 return result;
             }
         }
         return result;
     }

     public void collectExpressionInfo(ExpressionInfo info) {
         if (fExpressions == null) {
             return;
         }
         for (Iterator iter = fExpressions.iterator(); iter.hasNext();) {
             Expression expression = (Expression) iter.next();
             expression.collectExpressionInfo(info);
         }
     }
 }

